Gold nanoparticles were grown on single-walled carbon nanotubes (SWNTs) coated with a thiol-functionalized ionic liquid resulting in the formation of core-shell structures referred to as SWNT-IL-Au nanohybrid materials. The nanohybrid materials were characterized by high-resolution transmission electron microscopy (HR-TEM), Raman-, and UV/Vis absorption spectroscopy. The nanohybrid materials were found to enter lysosomes in HeLa cells and show negligible cytotoxicity. Interestingly, they have an enhanced NIR absorption that is effectively transferred into heat to cause localized hyperthermia, resulting in rapid cell death; overall, the material appears to have excellent properties for photothermal therapeutic applications.